Altocumulus clouds, Altostratus clouds, Cirrus clouds, Cumulonimbus clouds, Cumulus clouds, Definitions, Ice crystals, The weather ahead

Flatlined

The recording raingauge, that is. A coupla drops is all that fell here in Catalina after some indications of cores around us later yesterday afternoon that were producing measurable rain. You can go to the U of AZ rainlog site to see some local amounts–the Pima County ALERT site is down right now. They’ll have some reports in the mountains and elsewhere, providing it wasn’t snow.  The most I’ve seen so far is 0.05 inches, lucky dogs.

Some nice cloud sights on a day of dramatic, icy development.  I wonder if you say the first Cumulus/Stratocumulus blob glaciating far to the WSW, beyond Twin Peaks?  I thought it would happen first toward the NW-N because the air got colder if you headed in those directions.  Yesterday’s cloud highlights, once again pioneering here the “novella-sized”, explanatory caption:

8:24 AM. Altocumulus overspreads the sky, briefly. Ac perlucidus translucidus (thin). Someday I think I will make you memorize ALL of the cloud names and their species and varieties.
8:59 AM. This beauty. It appears to be Cirrus of some kind (spissatus). But then yesterday I had written that there wasn’t going to be any Cirrus, and so I will term this, Altostratus translucidus altocumulotransmutatus. Pretty cloud, but ugly name (it really exists, and this patch really did originate via the glaciation of Altocumulus clouds.)
10:33 AM. Never have seen this sequence before. After the prior patch of ice cloud (some liquid cloud at top) moved off, a new wedge of Altocumulus (perlucidus) formed in the moist plume up there. Also very pretty I thought. Estimated height above ground, 18,000 feet, -25 C or even a little colder. Nature loves to form water drops before it freezes, as here, even at very low temperatures.
12:58 PM. Rise of the Cumulus machine…. Here, beyond Twin Peaks, is the first glaciating cluster of Cumulus/Stratocumulus responding to the cooling aloft and a bit of surface heating below.
2:04 PM. Locally, our Cumulus remained small, but in the distance is the icy tops associated with the line of sprinkles its not drizzle that came through later in the afternoon, enhanced by further Cumulus deepening around here as the afternoon progressed. Pretty sky.
2:38 PM. Heavier Cumulus bases line up against the Catalina Mountains near Charoleau Gap. Looking better for precip here at this point.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


2:39 PM. A tell tale ice plume is amid these smaller clouds telling the observer that it is damn cold up there for such small clouds to produce so much ice (though the one that produced this little plume would have been taller than those around it) How cold? Estimate the top of the one that produced this was at least
lower than -15 C (5 F). Ice crystal concentrations? Estimate at least a few per liter of air at this time when you see an ice plume like this. Pretty soon you’ll get that Cloud Maven tee.

3:58 PM. By this time it looked very promising for a few hundredths of rain.
5:36 PM. But after all the bluster, just a trace of rain here.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The weather ahead: measurable rain!?

I am sure, that due to our fine array of weather practitioners on TEEVEE (ones that make an incredible amount of money, mind-boggling really, and ones that have the same kind of fun doing weather forecasting as I do) that rain is in the offing for Catalina in the days ahead.  So why bludgeon the topic here?  Well, let’s guess a range of amounts that could occur, bottom and top, based on SOP-eyeball of weather patterns and goofy, variable progs:

Last night’s Canadian run, has a near miss now, rain partitioned to the SE of us.  Booo!  But, then rain with a follow up system on Jan. 1st, maybe with some snow in it here.  So between the first threat and the second, both happening between the evening of December 30th and the evening of the 1st, the range has to be wild, maybe not useful.   At the bottom, we could be completely bypassed in measurable rain from two strong troughs (we’re still in a “trough bowl” BTW), but I guess if you’re in a drought, you only get misses.  But, being the optimist, AND with our own USA! model indicating measurable rain as of last night’s run, the range of amounts over the four days of chances, has to be from a trace to 0.50 inches at most.  So, a range with all the factors at play is not too useful.

The average of those two, 0.25 inches, often works out as the closest estimate.  Let’s see what the U of AZ has this morning…  Oops, no update, budget cuts strike some more!

 

The End.